<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        * {
            margin: 0px;
            padding: 0px;
        }

        .box {
            margin: 100px auto;
            width: 510px;
            height: 300px;

        }

        .box div {
            float: left;
            width: 100px;
            height: 300px;
            border: #5EFF5E solid 1px;
            margin-left: -1px;
            position: relative;
        }
        .box div:hover{
            z-index: 1;
            border: red solid 1px;
        }

    </style>
</head>
<body>
<div class="box">
    <div class="box1" ></div>
    <div class="box2"></div>
    <div class="box3"></div>
    <div class="box4"></div>
    <div class="box5"></div>

</div>

</body>
</html>